Posts Tagged ‘prediction’

The title of this post is identical to the title of a chapter in Lisa Feldman Barrett’s revolutionary book “HOW EMOTIONS ARE MADE.” Both pleasant and unpleasant feelings come from an ongoing process inside us called interoception. Interoception is our brain’s representation of all sensations from our internal organs and tissues, the hormones in our blood, and our immune systems. This interoceptive activity produces the spectrum of basic feeling from pleasant to unpleasant, from calm to jittery, and completely normal.

The intrinsic activity in our brains is not random; it is structured by collections of neurons that consistently fire together, called intrinsic networks. An intrinsic network has a pool of available neurons. Each time a network does its job, different groupings of its neurons fire in synchrony. Intrinsic brain activity is the origin of daydreams, imagination, mind wandering, and reveries. Dr, Barrett calls these activities simulations. We simulate what we might experience in the world. They assist in helping us to interact with the world. Intrinsic brain activity ultimately produces every sensation we experience, including our interoceptive sensations, which are the origins of our most basic pleasant, unpleasant, calm and jittery feelings.

Our brains, with only past experiences as a guide, make predictions. These predictions take place at a microscopic scale as millions of neurons talk to one another. These neural conversations try to anticipate every fragment of sight, sound, smell, taste, and touch that we experiences, and every action we will take. These predictions are our brains’ best guesses of what’s going on in the world around us and how to deal with it to keep us alive and well. Through prediction our brains construct the world we experience. It combines bits and pieces of our past and estimates how likely each bit applies to our current situation. Prediction is such a fundamental activity of the human brain that some scientists consider it the brain’s primary mode of operation. Predictions not only anticipate sensory input from outside our skulls, but also explain it. Our brains also use predictions to initiate our body’s movements, such as reaching our arm out to pick up an apple or dashing away from a snake. We are our brains, and the whole cascade of events is caused by our brains’ predictive powers.

If our brains were merely reactive, they would be too inefficient to keep us alive. We are always being bombarded by sensory input. One human retina transmits as much visual data as a fully loaded computer network connection in every waking moment. Now multiply that by every sensory pathway we have.

Evolution wired our brains for efficient prediction. The brain predicts far more visual input than it receives. Through prediction and correction our brains continually create and revise our mental models of the world. It’s an enormous, ongoing simulation that constructs everything we perceive which determine how we act. However predictions are not always correct, when compared to actual sensory input, and the brain makes adjustments.

Dr, Barrett notes that prediction efforts are not problems. They’re a normal part of the operating instructions of our brains as they take in sensory input. She continues, “Without prediction error, life would be a yawning bore. Nothing would be surprising or novel, and therefore our brains would never learn anything new.” She goes on to summarize, “the brain is not a simple machine reacting to stimuli in the outside world. It’s structured as billions of prediction loops creating intrinsic brain activity. Visual prediction, auditory predictions, gustatory predictions, somatosensory predictions, olfactory predictions, and motor predictions travel throughout the brain, influencing and constraining each other. These predictions are held in check by sensory inputs from the outside world, which our brains may prioritize or ignore.”

The most important mission of the brain is predicting the energy needs of the body. Our inner-body movements and their interoceptive consequences occur every moment of our lives. Our brains must keep our hearts beating, our lungs breathing, and our glucose metabolizing even when we’re not playing sport, even when we are sleeping or resting. Therefore interception is continuous, just as the mechanics of hearing and vision are always operating, even when we aren’t actively listening or seeing. However, sometimes we experience moments of intense interoception as emotion. In every waking moment, our brains give our sensations meaning. Some of these sensations are interoceptive sensations, and the resulting meaning can be an instance of emotion.

Dr. Barrett’s presentation of the interoceptive network is detailed and highly technical. If interested, please read the book. What is important for the purpose of this blog is the concept of a body budget that the brain needs to keep our hearts beating, lungs breathing, and our glucose metabolizing. The requirements of the body budget strongly affect our interoceptive network and the emotions that emerge from this interoceptive network.